From: Alexei Starovoitov <ast@kernel.org>
To: "David S . Miller" <davem@davemloft.net>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>,
Edward Cree <ecree@solarflare.com>,
Jakub Kicinski <jakub.kicinski@netronome.com>,
<netdev@vger.kernel.org>, <kernel-team@fb.com>
Subject: [PATCH bpf-next 05/13] selftests/bpf: add tests for stack_zero tracking
Date: Thu, 14 Dec 2017 17:55:09 -0800 [thread overview]
Message-ID: <20171215015517.409513-6-ast@kernel.org> (raw)
In-Reply-To: <20171215015517.409513-1-ast@kernel.org>
From: Alexei Starovoitov <ast@fb.com>
adjust two tests, since verifier got smarter
and add new one to test stack_zero logic
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
---
tools/testing/selftests/bpf/test_verifier.c | 66 ++++++++++++++++++++++++++++-
1 file changed, 64 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 88f389c6ec48..eaf294822a8f 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -5649,7 +5649,7 @@ static struct bpf_test tests[] = {
"helper access to variable memory: size > 0 not allowed on NULL (ARG_PTR_TO_MEM_OR_NULL)",
.insns = {
BPF_MOV64_IMM(BPF_REG_1, 0),
- BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_2, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -128),
BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -128),
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 64),
@@ -5884,7 +5884,7 @@ static struct bpf_test tests[] = {
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -24),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -16),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
- BPF_MOV64_IMM(BPF_REG_2, 0),
+ BPF_MOV64_IMM(BPF_REG_2, 1),
BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -128),
BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_10, -128),
BPF_ALU64_IMM(BPF_AND, BPF_REG_2, 63),
@@ -9056,6 +9056,68 @@ static struct bpf_test tests[] = {
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_SCHED_CLS,
},
+ {
+ "calls: caller stack init to zero or map_value_or_null",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 4),
+ /* fetch map_value_or_null or const_zero from stack */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1),
+ /* store into map_value */
+ BPF_ST_MEM(BPF_W, BPF_REG_0, 0, 0),
+ BPF_EXIT_INSN(),
+
+ /* subprog 1 */
+ /* if (ctx == 0) return; */
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 8),
+ /* else bpf_map_lookup() and *(fp - 8) = r0 */
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_2),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_map_lookup_elem),
+ /* write map_value_ptr_or_null into stack frame of main prog at fp-8 */
+ BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map1 = { 13 },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ },
+ {
+ "calls: stack init to zero and pruning",
+ .insns = {
+ /* first make allocated_stack 16 byte */
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0),
+ /* now fork the execution such that the false branch
+ * of JGT insn will be verified second and it skisp zero
+ * init of fp-8 stack slot. If stack liveness marking
+ * is missing live_read marks from call map_lookup
+ * processing then pruning will incorrectly assume
+ * that fp-8 stack slot was unused in the fall-through
+ * branch and will accept the program incorrectly
+ */
+ BPF_JMP_IMM(BPF_JGT, BPF_REG_1, 2, 2),
+ BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
+ BPF_JMP_IMM(BPF_JA, 0, 0, 0),
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
+ BPF_LD_MAP_FD(BPF_REG_1, 0),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+ BPF_FUNC_map_lookup_elem),
+ BPF_EXIT_INSN(),
+ },
+ .fixup_map2 = { 6 },
+ .errstr = "invalid indirect read from stack off -8+0 size 8",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_XDP,
+ },
};
static int probe_filter_length(const struct bpf_insn *fp)
--
2.9.5
next prev parent reply other threads:[~2017-12-15 1:55 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-15 1:55 [PATCH bpf-next 00/13] bpf: introduce function calls Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 01/13] bpf: introduce function calls (function boundaries) Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 02/13] bpf: introduce function calls (verification) Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 03/13] selftests/bpf: add verifier tests for bpf_call Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 04/13] bpf: teach verifier to recognize zero initialized stack Alexei Starovoitov
2017-12-15 1:55 ` Alexei Starovoitov [this message]
2017-12-15 1:55 ` [PATCH bpf-next 06/13] libbpf: add support for bpf_call Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 07/13] selftests/bpf: add bpf_call test Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 08/13] selftests/bpf: add xdp noinline test Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 09/13] bpf: add support for bpf_call to interpreter Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 10/13] bpf: fix net.core.bpf_jit_enable race Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 11/13] bpf: x64: add JIT support for multi-function programs Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 12/13] bpf: arm64: " Alexei Starovoitov
2017-12-18 15:29 ` Arnd Bergmann
2017-12-18 15:51 ` Daniel Borkmann
2017-12-18 17:55 ` Alexei Starovoitov
2017-12-15 1:55 ` [PATCH bpf-next 13/13] selftests/bpf: additional bpf_call tests Alexei Starovoitov
2017-12-17 19:38 ` [PATCH bpf-next 00/13] bpf: introduce function calls Daniel Borkmann
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